RESUMEN
RATIONALE: Extraosseous Ewing's sarcoma is a rare tumor which is aggressive with poor prognosis; it can occur anywhere in the body, but scantily in the pancreas. Pancreatic Ewing's sarcoma is not reported commonly, with inconsistent clinical manifestations. In this regard, early recognition of this disease is very important for the patient's sake. PATIENT CONCERNS: A 16-year-old boy presented with left lower quadrant abdominal pain for 2 months, and left flank pain with dysuria for 1 month. DIAGNOSIS: Abdominal and renal ultrasonography found a mass between the spleen and left kidney as well as left renal pelvic dilatation. Abdominal computed tomography found a heterogenous mass derived from the tail of the pancreas. Serial examinations revealed that the mass was a pancreatic Ewing's sarcoma. Furthermore, no metastasis was documented. INTERVENTIONS: The tumor was totally excised after 6 months of chemotherapy, which included 10 courses of neoadjuvant chemotherapy with vincristine, epirubicin, and cyclophosphamide, alternating with ifosfamide and etoposide. The patient completed consolidation chemotherapy with vincristine, epirubicin, and cyclophosphamide, alternating with ifosfamide and etoposide for 5 courses. Radiotherapy was applied to the tumor-involved region and tumor bed. OUTCOMES: To date, the malignancy has not recurred since the treatment was completed 4 years ago. There are no complications from the treatment for the patient. LESSONS: The pancreas is a very rare extraosseous location for Ewing's sarcoma. Pancreatic extraosseous Ewing's sarcoma should be regarded as a differential diagnosis of non-urinary originated left flank pain with dysuria in adolescents.
